Amino-functional silsesquioxane copolymer coatings

Abstract

Coatings containing a silsesquioxane copolymer are described. The silsesquioxane copolymer comprises amino-functional repeat units and non-functional repeat units. Methods for preparing such coatings using hydrolysable silanes are also described. Articles incorporating such coatings, including retroreflective articles are also described.

1 . A coating comprising an amino-functional silsesquioxane having amino-functional repeat units and non-functional repeat units, wherein the non-functional repeat units comprise non-functional groups selected from the group consisting of alkyl-groups and aryl-groups consisting of hydrogen and carbon. 
     
     
         2 . The coating of  claim 1 , wherein the amino-functional silsesquioxane is the hydrolyzed product of at least one amino-functional, hydrolysable silane according to formula:
   R AM —Si—(R) 3  
   
       and at least one non-functional, hydrolysable silane according to formula:
   R NF —Si—(R) 3  
 
 
       wherein:
 R AM  is an amino-functional group; and 
 R NF  is a non-functional group selected from the group consisting of alkyl-groups and aryl-groups consisting of hydrogen and carbon; and 
 each R is, independently, a hydroxyl group or a hydrolysable group. 
 
     
     
         3 . The coating of  claim 2 , wherein at least one amino-functional group is an aminoalkyl-group. 
     
     
         4 . The coating of  claim 2 , wherein at least one amino-functional, hydrolysable silane is an aminoalkyltrihydroxy silane or an aminoalkyltrialkoxy silane. 
     
     
         5 . The coating of  claim 4 , wherein the at least one amino-functional, hydrolysable silane is selected from the group consisting of aminopropylsilanetriol, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, and combinations thereof. 
     
     
         6 . The coating of  claim 2 , wherein at least one amino-functional group is an aminoalkylaminoalkyl-group. 
     
     
         7 . The coating of  claim 6 , wherein at least one amino-functional, hydrolysable silane is selected from the group consisting of aminopropylaminoethyltrimethoxysilane, aminopropylaminoethyltriethoxysilane, aminoethylaminopropyltrimethoxysilane, aminoethylaminopropyltriethoxysilane, and combinations thereof. 
     
     
         8 . The coating according to  claim 2 , wherein the non-functional, hydrolysable silane is selected from the group consisting of an alkyltrihydroxy silane, an akyltrialkoxy silane, an aryltrihydroxy silane, an aryltrialkoxy silane, and combinations thereof. 
     
     
         9 . The coating of  claim 8 , wherein the non-functional silane is selected from the group consisting of ethyltrialkoxy silane, phenyltrialkoxy silane, and combinations thereof. 
     
     
         10 . The coating according to  claim 2 , wherein a ratio MR NF  is defined as MR NF =M NF /(M NF +M AM ), where M NF  moles of the nonfunctional silane(s) and M AM  is the moles of amino-functional silane(s); and wherein MR NF  is between 0.05 and 0.5, inclusive. 
     
     
         11 . The coating of  claim 10 , wherein MR NF  is no greater than 0.4. 
     
     
         12 . The coating of  claim 10 , wherein MR NF  is no greater than 0.2. 
     
     
         13 . The coating of  claim 10 , wherein MR NF  is at least 0.07. 
     
     
         14 . The coating according to  claim 1 , further comprising a non-ionic surfactant. 
     
     
         15 . An article comprising a substrate and the coating according to  claim 1  bonded to a surface of the substrate. 
     
     
         16 . The article of  claim 15 , wherein the substrate comprises a retroreflective sheeting. 
     
     
         17 . The article of  claim 15 , further comprising an ink bonded to the coating.